If the receiver says duel conversion, you must use a duel conversion crystal. THe frequincy must match ( aircraft fm receivers in the USA are 72mhz, and I would only use the sam manuifacurers crystal as the receiver. Tower Hobbys (www.towerhobby.com) carrys a lot of receivers, and matching crystals, so you can go to their site and search for your receiver and then see what crystal goes with it. You can call them and see what they have for your setup , too. Oh Yeah, what ever channel your TX transmits on is what channel your RX should be.
Last, resoldering an antennae won't hurt anything if it's just broken in two ,,,just do a range check before flying, as you should every flying session anyway.